Objective To study changes of DNA content in human spleen nuclei and seek an experimental method for estimation of the postmortem interval(PMI)using computerized image-analysis technique(CIAT).Methods Smear sections from spleen sampled were collected in 36 cadavers with known the accurate PMI respectively every hour within the first 36 hours after death,which were then fixed with cold Carony fixation.The smeared sections were stained by Feulgen-van's staining method.3 indices for spleen nucleic DNA including integral optical density(IOD),average optical density(AOD)and average gray(AG)were measured using the CIAT.Results IOD and AOD in the spleen nuclei declined regularly,whereas AG increased with the extension of PMIs in 36 hours.Conclusion There are definite relationships between the PMI and gray parameters(IOD、AOD and AG)representing the DAN content of nucleic DNA in the spleen in 36 hours after death,which may be used for estimation of PMI.

Liposome is an artificially prepared spherical vesicle that has a phospholipid bilayer. Given that the basic structure of its biological membrane is also a lipid bilayer membrane, liposome shares similar structures with body cells Therefore, liposome has good biocompatibility and advantages such as biodegradability, low immunogenicity, and subtle toxicity. Liposome has been widely ap-plied as an effective drug carrier. Studies on liposome-encapsulated fluorescent dye on tumor tracing have been reported in recent years. Liposome can become a more advantageous transport carrier with continuous development of surface modification materials and prepa-ration methods. The long cycle, targeted liposome-encapsulated drugs, and fluorescent dye have become the focus of interest for several researchers. This article mainly discusses the application and progress of long cycle and targeted liposome in cancer research.

BACKGROUND: The water molecules and biological macromolecules in human tissue may combine to form hydrate composite. Different types of macromolecules show different approaches to combine with water molecules. OBJECTIVE: To discuss the basic form of water molecules combined with biological macromolecules. METHODS: The theoretical hypothesis of texture composite hydration system was proposed. The relevant literatures were retrieved through the computer to discuss these issues. RESULTS AND CONCLUSION: According to the role of water in the hydrate composite, the composite ways can be divided into the following 4 groups. ①Surfaca composite: Hydrated membrane layers can form on the surface of globular protein or DNA molecules. The hydrated membrane layer shows that the speed of water molecular and hydrate density were reduced gradually from surface to inside. The hydrated layer makes the shape and physical state of the macromolecules stabilized, and it plays important role in forming of TCHS.②Swelling composite: As a result of the strong hydration of glycosaminoglycans, the hydrated proteoglycan often swells and shows high viscosity and hydrogel character. The hydrated proteoglycan play some mechanicalroles in connective tissue. For example, it can make the cartilage have a strong deformation-resistibility.③Hydrophobic composite: Hydr0phobic effect drives structural rearrangement, including the formation of bilayers (Bio-membrane). This hydrophilic-hydrophobic-hydrophilic "sandwich" structure is conducive to the self-stability in mechanics, combination with membrane protein and transmembrane transport. ④Slit composite: A lot of slit spaces with nano scale were existing inside and outside of the cells. Aqueous solution in the slit spaces shows some abnormal characters such as higher viscosity and lower ice point, because of the rearrangement of water molecules. Slit composite and surface composite have some universality, and it can be regarded the former as a special case of the latter. The classification way mentioned above has not any absolute connotations. However, the rational utilization of these hydration composite ways will be conducive to research the theory on textural composite hydrate system.

Two types of catheter made of polymeric hydrogel were prepared and their mechanical properties were studied. The results showed PVA hydrogel catheter was prepared by repeated freezing-thawing cycles of PVA solution in mould. Another type of catheter (PVA-DMSO - hydrogel ) was prepared by cooling the PVA solution containing 10%wt DMSO in mould. The tensile strength (30～40MPa)and elongation(380 %～400%) of these two types of catheter were comparable with those of commercial PVC catheter and silicone rubber catheter. But the elastic modulus of PVA-DMSO hydrogel catheter was 10MPa,near to silicone rubber catheter and that of PVA hydrogel catheter was only 4MPa. γ-ray irradiation for sterile made 40%～50% loss of tensile strength for both catheter. Dipping in hibitane aqueous solution didn\'t affect mechanical properties.The obvious difference in mechanical properties was due to the difference in the orientation of PVA molecule chain and crystalline structure.

A new kind of medical sponges,ionic polyvinyl alcohol sponges(i-PVA sponges)were prepared by surface-grafting of acrylic acid onto acetal-PVA sponges.i-PVA sponges obtained show excellent hydrophilicity and water-absorption.The i-PVA sponges are three dimentional porous network.Because there are great amount of carboxyl and sodium carboxylate groups on PVA molecule chains,the speed of water absorption and water-absorptivity is >2.9mm/s and >15 times respectively.That is,in the case of the cataract-extraction,the polyion-modified sponges much more advantageous than any traditional nonionic polymer sponges.

Nowadays, health care products based on static magnetic fields (SMF) and merchandise of magnetic therapy are popular around the world. But the biomedical effects of SMF to animals or human beings remain a widely concerned controversy. In this paper, the recent researches in China and abroad about the biomedical effects of SMF were reviewed in three levels: the cellular, animal and human levels. Nevertheless, these data were not consistent with each other and even some contradicts others' researches. So, it is necessary to do more and further studies on SMF dosing regiman, sham control magnetic device and blinding procedures to obtain the optimal magnetic intensity, the desired therapeutic effects in practical cases and prepare for applying the SMF in biomedical fields more effectively in the future.
Animals ; Humans ; Magnetic Field Therapy ; methods ; Magnetic Fields ; Neoplasms ; therapy ; Pain ; prevention & control

Objective To investigate the prognosis value of pulmonary infection score and acute physiology and chronic health evaluation to acute exacerbation of COPD with type 2 respiratory failure. Methods 112 cases with acute exacer-bation of COPD with type 2 respiratory failure were selected as research subjects in our hospital from February 2011 to February 2014,scores of two scoring methods,actual mortality with different scores of two scoring methods,ROC curve predicted mortality of two scoring methods to chronic obstructive pulmonary disease with acute exacerbation of respira-tory failure of survival group and death group were compared. Results There were no significant differences between the two groups in PaO2、pH、PaCO2 and HCO3-(t=1.742, 1.647, 1.791, 1.082, P>0.05);but the levels of AG and poten-tial HCO3-in death group were higher than those in survival group(t=10.865, 5.993, P<0.05). APACHEⅢ,CPIS scores of survival group significantly were lower than the death group, the differences were statistically significant (t=6.254,4.397,P<0.05). Mortality of APACHⅢ score ≥25 and CPIS score ≥6 were significantly higher than patients with lower than that value, the differences were statistically significant(χ2=10.264,7.351,P<0.05). CPIS predict mortality acute exacerbation of COPD with type 2 respiratory failure, the area under the ROC curve was 0.867,APACHEⅢpredict mortality acute exacerbation of COPD with type 2 respiratory failure, the area under the ROC curve was 0.938. Conclusion CPIS and APACHEⅢ has certain prognostic value to acute exacerbation of COPD and type 2 respiratory failure,but APACHEⅢ resolution are better, it can provide a reference for disease prediction, it is worthy of applica-tion and promotion in clinical.

Objective To evaluate the efficacy of volume therapy guided by stroke volume variabil-ity ( SVV) in the patients undergoing surgery for severe traumatic brain injury. Methods Thirty patients of both sexes with severe traumatic brain injury, aged 18-64 yr, of American Society of Anesthesiologists physical status Ⅲ, who were admitted to the hospital within 24 h after injury, with Glasgow Coma Scale ( GCS) score≤8, were divided into control group ( C group, n=15) and SVV group ( n=15) using a ran-dom number table method. In group C, conventional fluid administration was performed to maintain mean arterial pressure at 65-110 mmHg, central venous pressure at 5-12 cmH2 O and urine volume>1 ml·kg-1 ·h-1 . Fluid was given according to SVV, maintaining SVV≤13％ and mean arterial pressure at 65-110 mmHg in group SVV. Immediately after skin incision ( T0 ) , immediately after opening cerebral dura mater ( T1 ) , at 1 h after opening cerebral dura mater ( T2 ) , immediately after suturing cerebral dura mater ( T3 ) and at the end of operation ( T4 ) , blood samples were collected from the radial artery and inter-nal jugular venous bulb for blood gas analysis, the jugular venous oxygen partial pressure, jugular venous bulb oxygen saturation, blood lactate, arterial oxygen partial pressure, arterial oxygen saturation and Hbwere recorded, and the cerebral artery and arteriovenous blood O2 content difference and cerebral O2 extrac-tion rate were calculated. Blood samples were collected from the internal jugular venous bulb at T0-2 , T4 and 24 h after operation ( T5 ) for determination of S100β protein concentrations by enzyme-linked immunosor-bent assay. The intraoperative volume of fluid intake and output and consumption of vasoactive drugs were recorded. GCS scores were recorded immediately after admission to the operating room, and at 1, 3, 7 and 14 days after operation. The development of postoperative length of hospitalization and complications ( pul-monary infection and brain edema) was recorded. Glasgow Outcome Scale Score was used to assess the early postoperative quality of life. Results Compared with group C, the urine volume was significantly in-creased, the consumption of vasoactive drugs was reduced, jugular venous bulb oxygen saturation was in-creased at T2,3 , the cerebral O2 extraction rate was decreased at T2-4 , the serum S100β protein concentra-tion was decreased at T2 , and the GCS score was increased at day 3 after operation ( P<0. 05) , and no sig-nificant change was found in blood lactate, postoperative Glasgow Outcome Scale score or length of hospital-ization at each time point in group SVV ( P>0. 05) . Conclusion SVV-guided volume therapy can improve cerebral oxygen metabolism, ensure adequate tissue perfusion and reduce craniocerebral injury in the pa-tients undergoing surgery for severe traumatic brain injury.